How to migrate Minyaa Worklog Types to Tempo Worklog Attributes

We have been using Minyaa and it's Worklog Types to mark issues as billable. We have now implemented Tempo Timesheets and would like to phase out Minyaa. We would like to use Tempo's worklog attributes for marking issues as billable. Is there a way to transfer the billiable information from our old tickets using Minyaa to Tempo so that we can do historical reporting?